<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Radius</title>
    <style type="text/css">
        #yuan{
            width:100px;
            height:100px;
            background-color: blue;
            border-radius:50px;
        }
        #yj{
            width:100px;
            height:50px;
            background-color: blue;
            border-radius:10px;
            text-align: center;
            line-height: 50px;
        }
        #zj{
            width:100px;
            height:50px;
            background-color: blue;
            border-radius:0 10px 10px 0;
            text-align: center;
            line-height: 50px;
        }
        #bk{
            width: 100px;
            height: 30px;
            font-size: 14px;
            border: 10px solid red;
            border-image-source: url("border_image_button.png");
            border-image-slice: 0  14  0  14;
            border-image-repeat: round;
            line-height: 30px;
            text-align: center;
        }

        #yy{
            font-size: 20px;
            width: 80px;
            padding: 5px 10px;
            box-shadow: 10px 10px 3px gray;

        }
    </style>
</head>
<body>
    <div id="yuan"></div>
    <div id="yj">圆角</div>
    <div id="zj">直角</div>
    <div id="bk">边框背景</div>
    <div id="yy">盒子阴影</div>
</body>
</html>